1. Field of the Invention
This invention relates generally to an improved safety switch. An automatic safety stop is provided for a conventional type overhead track switch to prevent an overhead trolley from running off the track if the switch itself malfunctions.
2. Description of the Prior Art
Overhead track switches of both manual and semi-automatic type are well known in the prior art. A common problem with such switches has been in the provision of safety stops to prevent the overhead trolley from running off an open track in the case the switch malfunctions. The construction of the switch can be made so that the chance of a switch remaining open is decreased but normally in order to do this the operating mechanism becomes so positive in action that it is difficult and impractical to operate. If the switching mechanism is easy to operate then it is also common for it to malfunction. If a switch is left open or partially open and a trolley runs off the overhead track great damage can be the end result. Not only can expensive damage occur but also personal injury could be involved which most plants can ill afford. The following patents are known and may be pertinent to this invention. Haskins et al, U.S. Pat. No. 301,119, patented July 1, 1884; Louden, U.S. Pat. No. 891,493, patented June 23, 1908; Fitzgerald, U.S. Pat. No. 967,869, patented Aug. 16, 1910; and Ferris, U.S. Pat. No. 989,899, patented Apr. 18, 1911.